Calculating Video Quality Using NVIDIA GPUs and VMAF-CUDA

Video quality metrics are used to evaluate the fidelity of video content. They provide a consistent quantitative measurement to assess the performance of the…

Cem Moluluo
13 min readintermediate
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Overview

This article discusses the implementation of Video Multi-Method Assessment Fusion (VMAF) using NVIDIA GPUs and CUDA, highlighting the performance improvements and advantages of VMAF-CUDA over traditional CPU implementations. It details the collaboration between NVIDIA and Netflix, the key metrics used in VMAF, and the benefits of GPU acceleration in video quality assessment.

What You'll Learn

1

How to calculate VMAF scores using NVIDIA GPUs with CUDA

2

Why VMAF-CUDA is more efficient than CPU-based VMAF calculations

3

When to implement VMAF-CUDA in video processing pipelines for optimal performance

Prerequisites & Requirements

  • Understanding of video encoding and quality metrics
  • Familiarity with NVIDIA Video Codec SDK and CUDA Toolkit(optional)

Key Questions Answered

What is VMAF and how does it improve video quality assessment?
VMAF, developed by Netflix, is a video quality metric that combines human visual perception with machine learning techniques to evaluate video fidelity. It analyzes various quality factors and adapts to new content, making it a reliable tool for assessing video encoder performance.
How does VMAF-CUDA enhance performance compared to CPU implementations?
VMAF-CUDA utilizes NVIDIA GPUs to accelerate the calculation of VMAF scores, achieving up to 4.4x speedup in throughput and 37x lower latency at 4K compared to CPU implementations. This efficiency allows for real-time video quality monitoring without significant overhead.
What are the key elementary metrics used in VMAF?
VMAF evaluates video quality using metrics such as Visual Information Fidelity (VIF), Additive Distortion Measurement (ADM), and motion features. These metrics are essential for accurately assessing the perceived quality of video content.
What is the cost-effectiveness of using VMAF-CUDA over traditional CPU methods?
Using VMAF-CUDA can reduce the cost of calculating VMAF scores significantly, with estimates showing up to 75% savings compared to CPU implementations. This is due to the faster processing capabilities of NVIDIA GPUs, allowing for more efficient video quality assessments.

Key Statistics & Figures

VMAF throughput speedup
up to 4.4x
Compared to the open-source tool FFmpeg
VMAF latency reduction
up to 37x lower
At 4K resolution
FPS achieved at 4K with NVIDIA L4
178 FPS
During VMAF score calculation in FFmpeg
Cost to calculate VMAF for 1000 hours of 4K video
$24
Using NVIDIA L4 compared to $97 with Dual Intel Platinum 8480

Technologies & Tools

Software
Nvidia Video Codec SDK
Used for decoding images in the VMAF-CUDA implementation
Software
Cuda Toolkit
Required to compile VMAF-CUDA
Software
Ffmpeg
Integrated with VMAF-CUDA for video processing

Key Actionable Insights

1
Implementing VMAF-CUDA can drastically reduce video quality assessment time, allowing for real-time monitoring during encoding and transcoding processes.
This is particularly beneficial for applications that require immediate feedback on video quality, such as live streaming or video-on-demand services.
2
Utilizing the NVIDIA Video Codec SDK alongside VMAF-CUDA can streamline the video processing pipeline by keeping reference and distorted frames in GPU memory.
This approach minimizes memory transfer overhead and maximizes throughput, making it ideal for high-resolution video processing tasks.
3
Adopting VMAF-CUDA in your video processing workflows can enhance the overall quality of video outputs while reducing computational costs.
As demonstrated by partners like Snap, the ability to run VMAF calculations on the GPU allows for optimized encoding settings without incurring high computational costs.

Common Pitfalls

1
Assuming that VMAF-CUDA can be implemented without understanding the underlying video quality metrics.
A solid grasp of video quality metrics is essential for effectively utilizing VMAF-CUDA, as it directly impacts the accuracy of the assessments.
2
Neglecting to optimize memory transfers between CPU and GPU.
Inefficient memory management can lead to bottlenecks that negate the performance benefits of using GPU acceleration.

Related Concepts

Video Quality Metrics
Cuda Programming
Real-time Video Processing
Machine Learning In Video Encoding